-2b(b-7)=14-2b

Solution for -2b(b-7)=14-2b equation:

-2b(b-7)=14-2b

We move all terms to the left:

-2b(b-7)-(14-2b)=0

We add all the numbers together, and all the variables

-2b(b-7)-(-2b+14)=0

We multiply parentheses

-2b^2+14b-(-2b+14)=0

We get rid of parentheses

-2b^2+14b+2b-14=0

We add all the numbers together, and all the variables

-2b^2+16b-14=0

a = -2; b = 16; c = -14;
Δ = b2-4ac
Δ = 162-4·(-2)·(-14)
Δ = 144
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{144}=12$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-12}{2*-2}=\frac{-28}{-4}
=+7
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+12}{2*-2}=\frac{-4}{-4}
=1
$